Method for forming die protecting layer
A method for forming a die protecting layer is disclosed. The method comprises the following steps: providing a wafer with numerous dies on a first surface and a second surface, forming a transparent protecting layer on the second surface of the wafer. Clearly, the transparent protecting layer is directly formed on the backside or the front side of the wafer.
1. Field of the Invention
The invention relates to a method for forming a die protecting layer, and more particularly to a method for forming a die protecting layer on one side of a wafer opposite to the other side having dies.
2. Description of the Prior Art
For contemporary semiconductor field, the chip formed on the wafer has a minute and delicate structure, and usually is incorporated with other elements (such as capacitor or inductor) to form an integrated circuit. Hence, the chip usually is packaged after its formation and before its operation.
Since the conventional technology still has above mentioned drawbacks. It is desired to further develop new technologies to overcome the drawbacks.
SUMMARY OF THE INVENTIONOne main object of the invention is to provide a method for forming a die protecting layer to solve issues of production standard variation and unstable quality.
Another main object of the invention is to provide a method for forming a die protecting layer to decrease production cost and increase yield ratio.
Still a main object of the invention is to provide a method for forming a die protecting layer to increase convenience for the following package process.
The method of the invention comprises the following steps. First of all, a wafer having a plurality of dies, a first surface and an opposite second surface is provided, wherein the dies are on the first surface. Then a transparent polymer material and fluorescence materials are pre-mixed to form a transparent protecting material. Next the transparent protecting material is applied to and covers the first surface or the second surface. Finally, the transparent protecting material is cured by heating to form a transparent protecting layer.
BRIEF DESCRIPTION OF THE DRAWINGSIn the accompanying drawing forming a material part of this description, there is shown:
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings.
Furthermore, the key characters of the invention are related to the method of packing dies but are not related to the amendment(s) of dies' structures or dies' distribution. Therefore, to avoid the risk of confusing and to simply the drawings, all drawings only show the existence of dies and electrodes but never show the real shape of dies and electrodes.
Referring to
Referring to
The transparent polymer material of the transparent protecting material is then cured to form the transparent protecting layer 24 which covers the second surface. The transparent protecting material is heated to over a curing temperature to form the transparent protecting layer 24. The curing temperature is adjusted to a level until the dies 22 of the wafer 20 would be harmed. For example, the curing temperatures of general package materials such as epoxy are in the range of about 150˜200° C., the curing temperatures of the transparent polymer materials are in the range of about 150˜300° C.
The transparent protecting layer 24 can also be formed on the first surface of the wafer 20 instead of the second surface according to various package specifications. As shown in
Comparing to the conventional technologies, the invention forms the transparent protecting layer on either side of the wafer before the wafer is scribed while the conventional technologies scribe the wafer into dies and uses additional tools to mount the dies and apply the protecting layer thereon. Therefore, the invention can effectively simplify package process and decrease package cost. Moreover, all dies are separated after the protecting layer is formed.
Referring to
Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.
Claims
1. A method for forming a die protecting layer, said method comprising:
- providing a wafer having a plurality of dies, a first surface and an opposite second surface, wherein the dies are on the first surface;
- pre-mixing a transparent polymer material and fluorescence materials to form a transparent protecting material;
- applying said transparent protecting material to and covers said second surface; and
- curing said transparent protecting material by heating to form a transparent protecting layer.
2. The method according to claim 1, wherein said dies comprise light-emitting diodes.
3. The method according to claim 1, wherein said transparent polymer material comprises epoxy.
4. The method according to claim 1, wherein said transparent polymer material comprises Polyimide.
5. The method according to claim 1, wherein said transparent polymer material comprises Polymethyl Methacrylate.
6. The method according to claim 1, wherein said transparent polymer material comprises Acrylonitrile Butadiene Styrene copolymer resin.
7. The method according to claim 1, wherein said transparent polymer material comprises Polyetherimides.
8. The method according to claim 1, wherein said fluorescence materials comprise yellow fluorescence materials.
9. The method according to claim 1, wherein said fluorescence materials comprise white fluorescence materials.
10. The method according to claim 1, wherein said fluorescence materials comprise blue fluorescence materials.
11. The method according to claim 1, wherein said transparent protecting material is applied to said second surface by a spin-on process.
12. The method according to claim 1, wherein said transparent protecting material is applied to said second surface by a squeeze process.
13. The method according to claim 1, wherein said transparent protecting material is heated to a temperature in a range of about 150° C. to about 300° C. to form said transparent protecting layer.
14. A method for forming a die protecting layer, said method comprising:
- providing a wafer having a plurality of light-emitting diode dies, a first surface and an opposite second surface, wherein the dies are on the first surface;
- pre-mixing a transparent polymer material and fluorescence materials to form a transparent protecting material;
- applying said transparent protecting material to and covers said first surface; and
- curing said transparent protecting material by heating to form a transparent protecting layer.
15. The method according to claim 14, wherein said transparent polymer material comprises epoxy.
16. The method according to claim 14, wherein said transparent polymer material comprises Polyimide.
17. The method according to claim 14, wherein said transparent polymer material comprises Polymethyl Methacrylate.
18. The method according to claim 14, wherein said transparent polymer material comprises Acrylonitrile Butadiene Styrene copolymer resin.
19. The method according to claim 14, wherein said transparent polymer-material comprises Polyetherimides.
20. The method according to claim 14, wherein said fluorescence materials comprise yellow fluorescence materials.
21. The method according to claim 14, wherein said fluorescence materials comprise white fluorescence materials.
22. The method according to claim 14, wherein said fluorescence materials comprise blue fluorescence materials.
23. The method according to claim 14, wherein said transparent protecting material is applied to said first surface by a spin-on process.
24. The method according to claim 14, wherein said transparent protecting material is applied to said first surface by a squeeze process.
25. The method according to claim 1, wherein said transparent protecting material is heated to a temperature in a range of about 150° C. to about 300° C. to form said transparent protecting layer.
Type: Application
Filed: Apr 3, 2004
Publication Date: Oct 13, 2005
Inventors: Bor-Jen Wu (Taipei), Mei-Hui Wu (Hsiang)
Application Number: 10/818,156